The present invention relates to a forging device and a method for forging works chiefly made of aluminum, and particularly to the forging device and the method for heating works prior to both intermediate and final forming in one heating furnace.
In the conventional process of forming a flat or a pipe work to produce an automobile part, etc., plural process such as bending, roll forging, and rough die press are sequentially applied to thereby form complex-form works,precisely.
The forging device, for forging works by using a heating furnace, moves the works while heating the works in a heating furnace, takes the heated works out of the heating furnace when the works reaches to end point of the movement path, and intermediately forms the work, followed by final forming thereof.
Such forging device heats the works in its heating furnace prior to each of the processes to thereby improve the precision in formation of the works and lengthen life of a forging die.
Since the temperature of a work made of iron or steel hardly falls, it is enough to heat the work only once before executing first forming process, whereas the temperature of a work chiefly made of aluminum easily falls, and also the aluminum work needs to be heated at the most 400xc2x0 C. in the heating furnace when forming the work. Therefore, only once an aluminum work is heated in the beginning of formation process, the temperature of the work tends to fall during its formation process, deteriorating precision of the formation process as well as shortening life of dies.
In order to compensate for the defect in coping with an aluminum work, a work chiefly made of aluminum is forged by a forging device having plural small preheating furnaces, for heating the aluminum work before intermediately forming the aluminum work at each processing stage.
On the other hand, publicly-known technology in forging field uses a circular heating furnace in which a billet subject for heat processing is heated to a temperature most appropriate for forging while moving the billet along an annular path therein. J-P-A-Nos. 49-75407 and 49-78610 describe examples of the technique. Those attempts were thus made to introduce such annular heating furnace in forging device to achieve efficient outcomes of the entire forging process and to make the layout of the annular heating furnace compact.
In these prior arts, for heating a work in a heating furnace while moving the work along an annular path thereof, however, one heating furnace is provided only for one process.
Nevertheless, the forging device for forging a work chiefly made of aluminum needs to be equipped with plural heating furnaces each of which is to be separately installed for each of the processes, accompanied with work conveyance and transshipment facilities, and, as a consequence, the entire forging device and facilities have become large in size.
Further, because the necessity of separately coping with each of the heating furnaces causes the increase in heating energy consumption and in the man-hour control of the heating furnaces.
The present invention aims to solve the problems, and to provide a forging device and a method for efficiently heating a work chiefly made of aluminum in one heating furnace to thereby forge the work precisely and lengthen a die life of a forging device.
The present invention provides a forging device having: a heating furnace for heating a work while moving the work along a movement path; an intermediate processing means, connected to a point in the midst of movement path, for intermediately forming the work; an intermediate conveyance means for conveying the work from the heating furnace to the intermediate processing means and for conveying the intermediately formed work from the intermediate processing means to the heating furnace; and a final processing means for finally forming the intermediately formed work reheated in the heating furnace.
A forging device of the present invention uses one heating furnace to heat a work prior to both intermediate and final forming processes, and thereby enabling the installation area of the forging device to be reduced and the work to be heated efficiently.
Further, in the forging device of the present invention, the movement path in the heating furnace can be made annularly. Since the movement path is made annularly, the installation area of the forging device can be reduced. And, since plural works are heated in the heating furnace while being moved along the movement path, the plural works can be heated efficiently.
Furthermore, in the forging device of the present invention, an opening/closing door can be provided, for conveying the works to the intermediate processing means, to be installed on the side wall of the heating furnace.
Moreover, in the device of the present invention, plural works can be loaded onto a conveyance tray, and can be moved along the movement path in the heating furnace, and an intermediate conveyance means can be provided to convey the works between the heating furnace and the neighborhood of the intermediate processing means.
According to the present invention, because plural works can be coped with in the heating furnace and by the intermediate conveyance means at a time, the overall processing of works can be coped with efficiently compared with the processing where works is processed one by one.
Further, in the present invention, the intermediate conveyance means can be composed of a guide rail installed so as to take works out of the heating furnace and a rotary table to enable part of the guide rail to be moved rotatively together with the works.
The use of the rotary table enables raw works and processed works to be easily interchanged with each other, and thereby enhancing the work efficiency.
Moreover, the present invention provides a forging method using the aforementioned forging device having: a conveyance step for conveying works into the heating furnace; first heating step for heating the works while moving them along a movement path inside the heating furnace; an intermediate conveyance step for conveying the works, in the midst of the movement path, from the heating furnace to the intermediate processing means; an intermediate forming step for forming the works by the intermediate processing means; an intermediate conveyance step for conveying the intermediately processed works from the intermediate processing means to a point in the midst of the movement path; the second heating step for heating the works, in the heating furnace while moving the remaining works along the movement path; a take-out step for taking the works being at the terminal of the movement path out of the heating furnace; and a final processing step for finally forming the works conveyed at the take-out step.
According to the present invention, works can be heated by one heating furnace prior to both intermediate and final forming processes, and thereby reducing the installation area of the entire forging device and heating the works efficiently.
The forging method of the present invention is particularly applicable to a work chiefly made of such material as aluminum work which easily gets cold.